Medical Physics Terminology

Terminology, Modeling, and Measurement in Medical Physics

• Terminology is the science of terms.
• Physics is the science of nature.
• Medical physics is a term of science that overlaps two fields: medicine and physics.
• Medical physics concerns the study of several fields of physics in the body, including:
  • Physical parameters that involve in the function of the body and affect the body (e.g., pressure, force, energy, power, and electricity).
  • Physics of body organs and systems (e.g., vision, hearing, skeletal, pulmonary, cardiovascular, and nervous systems).
  • Applications of physics in the practice of medicine (e.g., laser, sound and ultrasound, X-rays, CT scans, MRI, ECG, EEG, ERG).

Standard and Nonstandard Units in Medicine

• Standard units: some quantities in medicine are measured in the same units for measurement (e.g., force in newton, work in joule, power in watts).
• Nonstandard units: some quantities in medicine are measured in special units that are different from the units used outside of medicine (e.g., pressure in mmHg or cmHg instead of N/m² or dyne/cm², energy in kilocalorie or calorie instead of joule).

Repetitive and Nonrepetitive Measurements

• Repetitive measurements: include quantities that are measured in repetition per unit time (e.g., pulse rate, breathing rate, electrical signals from the brain).
• Nonrepetitive measurements: include quantities that are not repetitive or uniform (e.g., time of kidney function, food digestion, nerve signals, eye movement).

Accuracy of Measurement

• Medical measurements should be very accurate, with a low percentage of error to avoid risky results.
• Errors can occur due to measuring instruments, psychological reasons, and other factors.
• Inaccurate measurements can lead to false negative or false positive errors.

Reducing Diagnostic Errors and Measurement Uncertainties

• Ways to reduce errors and uncertainties:
  • Research into causes of misleading laboratory test values.
  • Repeating measurements.
  • Care in taking measurements.
  • Developing new clinical tests.
  • Improving instrumentation.
  • Using reliable instruments.
  • Calibration of instruments to standard or already calibrated instruments.

Medical Measurements and Treatment

• Medical measurements that precede treatment:
  • Routine measurements (e.g., body temperature, pulse rate, blood pressure, body weight).
  • Other required tests according to the patient's case (e.g., laboratory investigation, body signals investigation, machinery measuring instruments).

Applications of Physics in Medicine

• Sound in medicine:
  • General properties of sound.
  • The stethoscope.
  • Ultrasound picture of the body.
  • Ultrasound to measure motion.
  • Physiological effects of ultrasound in therapy.
• Light in medicine:
  • Measurement of light and its units.
  • Applications of visible light in medicine.
  • Applications of microscopes in medicine.
• Physics of the eyes and vision:
  • Defective vision and its correction.
  • Instruments used in ophthalmology.
• Laser in medicine:
  • Generation of laser light.
  • Applications to medicine.
• Physics of diagnostic X-rays:
  • Production of X-ray beams.
  • How X-ray is absorbed.
  • Fluoroscopy.
  • CT scan.
• Physics of nuclear medicine:
  • Units of radioactivity.
  • Basic instrumentation of nuclear medicine.
  • Radiation doses in nuclear medicine.
• Physics of radiation therapy:
  • Dose units in radiotherapy.
  • Principles of radiation therapy.
• Radiation detection:
  • Biological effects of ionizing radiation.
  • Radiation protection in radiation therapy.
  • Magnetic resonance imaging (MRI).

Terminology, Modeling, and Measurement in Medical Physics

• Terminology is the science of terms.
• Physics is the science of nature.
• Medical physics is a term of science that overlaps two fields: medicine and physics.
• Medical physics concerns the study of several fields of physics in the body, including:
  • Physical parameters that involve in the function of the body and affect the body (e.g., pressure, force, energy, power, and electricity).
  • Physics of body organs and systems (e.g., vision, hearing, skeletal, pulmonary, cardiovascular, and nervous systems).
  • Applications of physics in the practice of medicine (e.g., laser, sound and ultrasound, X-rays, CT scans, MRI, ECG, EEG, ERG).

Standard and Nonstandard Units in Medicine

• Standard units: some quantities in medicine are measured in the same units for measurement (e.g., force in newton, work in joule, power in watts).
• Nonstandard units: some quantities in medicine are measured in special units that are different from the units used outside of medicine (e.g., pressure in mmHg or cmHg instead of N/m² or dyne/cm², energy in kilocalorie or calorie instead of joule).

Repetitive and Nonrepetitive Measurements

• Repetitive measurements: include quantities that are measured in repetition per unit time (e.g., pulse rate, breathing rate, electrical signals from the brain).
• Nonrepetitive measurements: include quantities that are not repetitive or uniform (e.g., time of kidney function, food digestion, nerve signals, eye movement).

Accuracy of Measurement

• Medical measurements should be very accurate, with a low percentage of error to avoid risky results.
• Errors can occur due to measuring instruments, psychological reasons, and other factors.
• Inaccurate measurements can lead to false negative or false positive errors.

Reducing Diagnostic Errors and Measurement Uncertainties

• Ways to reduce errors and uncertainties:
  • Research into causes of misleading laboratory test values.
  • Repeating measurements.
  • Care in taking measurements.
  • Developing new clinical tests.
  • Improving instrumentation.
  • Using reliable instruments.
  • Calibration of instruments to standard or already calibrated instruments.

Medical Measurements and Treatment

• Medical measurements that precede treatment:
  • Routine measurements (e.g., body temperature, pulse rate, blood pressure, body weight).
  • Other required tests according to the patient's case (e.g., laboratory investigation, body signals investigation, machinery measuring instruments).

Applications of Physics in Medicine

• Sound in medicine:
  • General properties of sound.
  • The stethoscope.
  • Ultrasound picture of the body.
  • Ultrasound to measure motion.
  • Physiological effects of ultrasound in therapy.
• Light in medicine:
  • Measurement of light and its units.
  • Applications of visible light in medicine.
  • Applications of microscopes in medicine.
• Physics of the eyes and vision:
  • Defective vision and its correction.
  • Instruments used in ophthalmology.
• Laser in medicine:
  • Generation of laser light.
  • Applications to medicine.
• Physics of diagnostic X-rays:
  • Production of X-ray beams.
  • How X-ray is absorbed.
  • Fluoroscopy.
  • CT scan.
• Physics of nuclear medicine:
  • Units of radioactivity.
  • Basic instrumentation of nuclear medicine.
  • Radiation doses in nuclear medicine.
• Physics of radiation therapy:
  • Dose units in radiotherapy.
  • Principles of radiation therapy.
• Radiation detection:
  • Biological effects of ionizing radiation.
  • Radiation protection in radiation therapy.
  • Magnetic resonance imaging (MRI).